Secondary standard timer



Nov. 13, 1962 D. A. BLY

SECONDARY STANDARD TIMER 2 Sheets-Sheet 1 R w m %m N & R E. O V A W W. m K A M wfim V 1 6 Y B 0 5 Q Filed April 8, 1960 Nov. 13, 1962 BLY 3,063,233

SECONDARY STANDARD TIMER Filed April 8, 1960 2 Sheets-Sheet 2 ALLIIIIIIIIIII 4| lllllllll I ww 5 c WWV F/LELTE/Q PULSE T/MER fiECE/VIFR 05756701? 5/04/ 151? I F g. 7

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C JIJIJI 0.005 0,025 ran/5T 0, 0/0 556 SEC SEC, 704/5 HUUUUL INVENTOR DOA/4 Ely ATTORNEYS United States Patent 3,063,233 SECONDARY STANDARD TIMER Donald A. Bly, Lancaster, Pa., assignor to Hamilton Watch Company, Lancaster, Pa., a corporation of Pennsylvania Filed Apr. 8, 1960, Ser. No. 21,049 10 Claims. (Cl. 58--26) This invention relates to a secondary standard timepiece and more particularly to an electrical clock adapted to be synchronized by radio broadcast time signals such as those transmitted from the U.S. Government radio stations WWV and WWVH.

While secondary standards controlled by radio broadcarts are well known they uniformly involve a substantial modification of the basic timer system to be controlled and generally involve additional complex and expensive equipment. The size of the timing units as well as their cost are greatly increased and they often require regular inspection and frequent maintenance.

The present invention provides a radio controlled clock or timepiece of relatively simple, inexpensive construction requiring no major modifications of the basic timer sysmm. The control features of the present invention are completely electrical so that no complex or moving mechanical parts are required to maintain the clock under the control of the radio signals. The clock of the present invention is suitable for use as a very accurate secondary time standard with an accuracy closely approaching the accuracy of the radio signals.

It is therefore a primary object of thepresent invention to provide an improved secondary standard timer.

Another object of the present invention is to provide a completely electrical control for a radio controlled clock.

Another object of the present invention is to provide a secondary standard timer of increased accuracy and reliability.

Another object of the present invention is to provide a radio controlled timepiece of relatively simple and inexpensive construction.

These and further objects and advantages of the invention will be more apparent upon reference to the following specification, claims and appended drawings wherein:

FIGURE 1 shows the novel secondary standard timer of the present invention;

FIGURE 2 is a circuit diagram showing the electrical circuit for the timer of FIGURE 1;

FIGURE 3 is a schematic view illustrating timer corr'ection for a timer that is running fast;

FIGURE 4 is a schematic diagram illustrating timer correction for a timer that'is running slow;

FIGURE 5 shows a portion of a representative transmitting schedule for the US. Government radio stations WWV and WWVH;

FIGURE'6 shows the wave form for the seconds ticks transmitted by stations WWV and WWVH;

"FIGURE 7 is a block diagram showing the timer of FIGURE 1 incorporated in the over-all system of the present invention; and

FIGURE'S shows the waveforms at various points in the block diagram of FIGURE 7.

Referring to the drawings, FIGURE 1 shows the novel timer of the present invention which is constructed in the form of an electric clock or watch along the lines of the construction disclosed in assignees US. Patent No. 2,662,- 366 to Koehler. The timer generally indicated at 10 includes a base 12 supporting a plate 14. Posts 16 and 18 are secured to plate 14 and carry a bridge 20 which supports the balance wheel 22 and associated structure. Also shown is the regulator 24, a setting stem 26, and gear train assembly 28.

Patented Nov. 13, 1962 The timer 10 includes a pair of electrical coils 30 and 32 which surround suitable cores to form a pair of electromagnets. The electromagnet cores terminate in a pair of opposed pole pieces 34 and 36.

Mounted on the balance staff 38 is a rotor or armature 40 of suitable magnetic or magnetizable material. The balance Wheel and balance staff are rotated by means of periodic magnetic impulses from the electromagnets through pole pieces 34 and 36. By means of the contact mechanism 42 the electrical circuit through the coils 3t) and 32 is periodically closed at a time when the rotor 40 is out of alignment with the pole pieces so that the rotor receives a magnetic impulse tending to draw it into alignment with the magnetic lines of force passing between the oppositely polarized pole pieces 34 and 36.

Electrical energy from a battery, an electrical outlet such as a wall plug or any other suitable source of electrical energy is supplied to the coils 3i and 32 over a wire 44. The electrical current flows from wire 44 through suitable connectors to wire 46 and from Wire 46 to coil 30. Connection from coil 30 to coil 32 is by way of wire 48. From coil 32 the electrical circuit can be traced through Wire :50 to a contact supporting post 52 and the contact assembly 42. Post 52 is preferably insulated from plate 14 by a dielectric spacer 54. The electrical return to the source of electrical energy is through the contact assembly '42 to plate 14 and thence to the opposite side of the source which in most instances is grounded. The circuit includes a resilient spring arm as in Koehler Patent No.

2,662,366 and this is indicated at 39 in FIGURE 2.

An important feature of the present invention is the provision in the timer 10 for supplying electrical timing impulses to the system in order to synchronize the timer mechanism movement with the timing pulses. The timing pulses derived from the radio broadcast are applied to the timer by way of leads 56 and 58, as best seen,

in FIGURES 1 and 2. Timing lead 56 is electrically connected to lead 44 and timing lead 58 is electrically connected to the end of lead 50. As shown in FIGURE 2 the voltage source is preferably connected with its negative side to lead 44 and the time signal impulses are coupled to leads 56 and 58 with the polarity indicated so that negative going pulses are supplied through coils 30 and 32. The lower ends of the coils are preferably connected by a rectifier 60 which shorts out any positive voltages applied to the coils but constitutes an effective open circuit for the negative voltages indicated in FIGURE 2.

FIGURES 3 and 4 illustrate the synchronizing action of the timing pulses for a timer that is running too fast as in FIGURE 3 or too slow as in FIGURE 4. In FIG- URE 3 the direction of rotation of rotor 40 is indicated by the solid arrow and as can be seen rotor 40 is moving away from the electromagnet pole pieces 34 and 36. Since in the basic timer mechanism the balance wheel assembly and hence rotor 40 undergoes an integral number of complete oscillations each second, the timer, if running exactly on time, would be in the dashed line position indicated in FIGURE 3. It is apparent however that the rotor in FIGURE 3 is in advance of this position and should be slowed down. This is =accomplished by the application of the timing pulse to coils 30 and 32 which energizes the pole pieces 34 and 36 applying an impulse to rotor 40 which tends to retard 'it or bring it back into the air gap between pole pieces 34 and 36. This retarding impulse is indicated by the dashed arrow in FIGURE 3.

In FIGURE 4 the on-time position of rotor 46 is again indicated by dashed lines and the direction of rotation is indicated by the solid arrow. It is apparent that the rotor carried by the balance assembly in FIGURE 4 is running slow and that a pulse energization received by the coils and transmitted through pole pieces 34 and 36 applies a speeding-up impulse to rotor 40 indicated by the dashed line arrow in FIGURE 4 in a direction again tending to cause the rotor to line up with the magnetic field between pole pieces 34 and 36, that is causing it to be drawn into the air gap between the poles.

Although the timer of the present invention may be utilized with any electrical timing pulses of suitable size, shape and frequency, it is particularly adapted for use in conjunction with the timing signals broadcast by the U.S. National Bureau of Standards. As is well known the U.S. Government operates two broadcasting stations, WWV located in Beltsviile, Maryland near Washington, D.C., and WWVH in Maui, Hawaii.

in addition to other services, these stations broadcast alternate 440 cycle and 600 cycle tone signals along with an almost continuous series of 1000 cycle time bursts or ticks spaced exactly one second apart. A representative portion of a program from one of these two stations is illustrated generally in FlGURE 5. The stations each broadcast alternate tone signals of a frequency of 600 cycles and then of 440 cycles, the tone signals in each case being three minutes in duration, The tone signals are separated by two minute intervals during which only the seconds ticks occur. The 600 cycle tone is indicated at 52 in FIGURE 5 while the 440 tone three minute period is indicated at 64. The two minute interval between these tone signals is indicated at 66. The seconds bursts or ticks occur at intervals precisely one second apart and are continuous except that intervals of one minute are marked by omitting the tick at the beginning of the last second of the minute. In addition, station WWV is silent for approximately four minutes each day and WWVH is silent for periods of approximately three minutes four times each day.

it is to be understood that the seconds pulses from the transmitting station occur during the tone signal periods as well as between the tone signal periods. FIG- URE 6 illustrates the seconds tick or burst wherein the tone signal indicated at 68 is interrupted for a total period of exactly 40 milliseconds. The seconds tick is composed of discrete frequency components at intervals of 1.0 cycles per second. The WWV pulse consists of five cycles of 1000 cycles per second starting at the beginning of each second as indicated at 70. The WWVd pulse consists of six cycles of 1200 cycles per second starting at the same instant.

FTGURE 7 illustrates in block diagram form a circuit for modifying the signals from stations WWV or WWVH for use with the timer of FIGURE 1. Each of the block diagram elements of FIGURE 7 is conventional in itself and further description is deemed unwarranted. The signal from station WWV for example is detected in receiver 74 where the carrier is removed. The receiver may be tuned to any one of the six carrier frequencies at which station WWV broadcasts, that is 2.5 megacycles, 5 megacycles, l0 megacycles, megacycles, megacycles and megacycles. The output from receiver '74- with the carrier removed is a reproduction of the seconds burst 70 illustrated in FIGURE 6 as indicated at A in FIGURE 8.

During the times when the 440 and 600 cycle tone signals are being transmitted the output from receiver '74 will ordinarily include these tones as well, spaced in time from the seconds burst 76 indicated in FIG- URE 8. For this reason, it is necessary to incorporate a tone signal filter in addition to the detector indicated by block 78 in FIGURE 7. The filter for station WWV passes 1000 cycle signals and filters out and blocks the 600 and 440 cycles. For station WWVH the filter passes 120G cycle signals. The detector in block 78 rectifies the signal so as to obtain the envelope of the seconds burst as indicated at B in FIGURE 8. The signal then passes through a pulse shaper 80 which amplifies and shapes the envelope to the desired wave form as indicated at C in FIGURE 8.

In one embodiment the invention was operated from a. 1.5 volt battery type power supply. The synchronization pulses at the output of pulse shaper varied in pulse height from .50 to 1.00 volts and in pulse width from 25 to 50 milliseconds. The unit was controlled by pulses from station WWV and the balance motion ranged from one and one-fourth to one and three-eighths turns of the balance stair.

While the embodiment shown discloses a timer wherein the balance assembly oscillates through an integral number of complete oscillations per second, it is apparent that the base oscillation period may be varied as desired with the synchronizing repetition rate. Furthermore, it is apparent that pulse dividers may be employed so that any desired number of pulses may be skipped from the radio station source and every fifth or every tenth or other desired multiple pulse utilized to control the timer.

It is apparent from the above that the present invention provides a novel secondary standard timer of relatively simple and inexpensive construction having a completely electronic synchronization control. The construction shown has the advantage that the clocks ability to run without a synchronization pulse is inherent in the movement so that no relay or switching device external to the movement is required. Since the clock keeps good time to start with the period or periods of no pulse which may be caused among other things by radio interference, electrical storms or propagation difficulties can occur without substantial loss of synchronization or substantial inaccuracy in time of the secondary standard.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. A timing device comprising a balance assembly, paramagnetic rotor means carried by said balance assembly, means for applying a periodic magnetic impulse to said rotor to oscillate said balance assembly, and means for supplying a radio signal to said impulse applying means for synchronizing the oscillations of said balance assembly with said radio signal, said rotor means and said impulse supplying means being constructed so that the oscillation of said balance assembly is accelerated or retarded according to the position of said rotor member in relationship to said impulse means when said radio signal is supplied.

2. A timing device comprising a balance assembly, magnetizable rotor means carried by said balance assembly, electromagnetic means for applying a periodic magnetic impulse to said rotor to oscillate said balance assembly, and means for supplying a radio signal to said electromagnetic means for synchronizing the oscillations of said balance assembly with said radio signal, said rotor means and said electromagnetic means being constructed so that the operation of said balance assembly is accelerated or retarded according to the position of said rotor means in relationship to said electromagnetic means when said signal is supplied.

3. A timing device comprising a balance assembly including a balance stafi, a magnetizable rotor carried by said balance stafi, an electromagnet having oppositely polarizable poles spaced on opposite sides of the path of movement of said rotor, means for periodically applying an electric impulse to said electromagnet to oscillate said rotor and balance assembly, and means for supplying radio time signals to said electromagnet to synchronize the oscillations of said rotor and said balance assembly with said radio signals, said rotor and electromagnet being constructed so that the oscillation of said balance assembly is accelerated or retarded according to the position of said rotor in relationship to said electromagnet poles when said radio time signals are supplied.

4. A timing device according to claim 3 including a radio receiver coupled to said electromagnet.

5. A timing device according to claim 4 wherein said radio receiver is coupled to said electromagnet through a filter and detector.

6. A timing device according to claim 5 including a pulse shaper connected between said detector and said electromagnet.

7. A timing device according to claim 5 wherein said filter is a narrow band pass filter passing only 1000 cycle signals.

8. A timing device comprising a clock movement including a balance assembly having a balance staff, a magnetizable rotor carried by said balance staif, a pair of spaced electrical coils surrounding a pair of magnetic cores, said cores having oppositely polarizable poles spaced on opposite sides of the path of movement of said rotor, means connecting said coils in series for current flow, means connected across said coils for applying a periodic electrical impulse to said coils for energizing said clock movement and oscillating said balance assembly, a

5 radio receiver, and means connecting the output of said radio receiver across said coils for synchronizing said clock movement with the radio signals from said receiver, by accelerating or retarding the oscillation of said balance assembly according to the position of said rotor in relationship to said poles.

9. A timing device according to claim 8 wherein said receiver is connected to said coils through a 1000 cycle pass filter and a rectifier.

10. A timing device according to claim 9 including a rectifier connected across said coils and means for connecting said periodic impulse means and the output of said receiver across said coils with a polarity whereby said rectifier connected across said coils acts as an open circuit for said signals and as a short circuit for signals of opposite polarity.

References Cited in the file of this patent UNITED STATES PATENTS 2,662,366 Koehler Dec. 15, 1953 2,814,769 Williams Nov. 26, 1957 2,824,218 Gilliland Feb. 18, 1958 2,929,991 Skelton Mar. 22, 1960 FOREIGN PATENTS 89,079 Switzerland May 2, 1921 844,493 France Apr. 24, 1939 

